DIAGNOSIS: This is the 'ice full' alert. The sensor arm in the ice basket is stuck or obstructed, so the machine thinks the basket is always full and beeps to tell you to empty it.
FIX: Remove the ice basket. Manually lift and release the small plastic sensor lever inside the ice chute a few times to ensure it moves freely. Clear any stray ice chips lodged around it. Reinsert the basket, making sure it slides all the way in and depresses that lever.
IF THAT DIDN'T WORK: The basket itself might not be seated correctly. Take it out, turn it 180 degrees, and try reinserting it. Sometimes the alignment is off by a millimeter.
HEADS UP: If you use a different container to catch ice, you must keep that sensor lever manually depressed, or the beeping will continue non-stop.